Different Types of Protein molecules, Collagen, Elastin, Karetin, Myoglobin.

1. SIMPLE AND CONJUGATED PROTAIN :-

Q1 Example of simple proteins? 

A) Serum

B) Albumin

C) Insulin 

D) Option a b c

Ans - D

2) Following are the examples of conjugated protein except? 

A) Hemoglobin 

B) Glycogen Phosphorylase

C) Adrenaline 

D) Mucin

Ans - C

3) There is a functional protein which consists of a polypeptide chain and a non protein component, this Type of protein is called? 

A) Glycoprotein 

B) Metalloprotein

C) Simple protein

D) Conjugated protein 

Ans - D

4) Non protein component of a conjugated protein is called? 

A) Non conjugated protein  

B) Apoprotein 

C) Activator group 

D) Prosthetic group 

Ans - D

5) Prosthetic Group of a protein is also known as all of the following except? 

A) Non conjugated protein 

B) Helper groups

C) Hetero groups 

D) Co - factors

Ans - A

6) Protein with prosthetic group called?

A) Apoprotein

B) Holoprotein

C) Non protein group 

D) Glycoprotein 

Ans - B

7) Protein with non prosthetic group called?

A) Apoprotein

B) Holoprotein

C) Non protein group 

D) Glycoprotein

Ans - A

8) Which of the following is Long Rod shaped protein?

A) Globular protein 

B) Fibrous protein 

C) Receptor protein 

D) Collagen protein 

Ans - B

9) Keratin is a example of?

A) Globular protein 

B) Fibrous protein 

C) Receptor protein 

D) Collagen protein 

Ans - B

10) Which of the following is compact, spherical & water soluble molecules?

A) Globular protein 

B) Fibrous protein 

Ans - A

11) Which of the following is a silk fibre?

A) Keratin (alpha helix)

B) Fibroin (beta sheets)

Ans - B

12) Fibre of wool is?

A) Keratin (alpha helix)

B) Fibroin (beta sheets)

Ans - A

13) Which of the following is most abundant protein in human body?

A) Collagen 

B) Keratin 

C) Insulin 

D) Glycogen 

Ans - A

14) Where does the most collagen present inside the cell?

A) Golgy apertures 

B) ER

C) ECM

D) Option B & C

15) Which of the following statement about collagen is incorrect?

A) Made up of 3 right Alpha helix.

B) It is triple standard helical structure.

C) Made up of 3 left Alpha helix.

D) Collagen is a right handed protein molecule.

Ans - A

16) Alpha helix of a Collagen molecule follow which of the following sequence?

A) Gly - Pro - 3 or 4-hydroxyproline or 5-hydroxylysine

B) Gly - Pro

C) 4-hydroxyproline or 5-hydroxylysine

D) Gly - Pro - Ala

Ans - A

17) Proline converts into Hydoxyproline by the enzyme? 

A) Lysil hydroxylase

B) Propyl hydroxylase

C) Vitamin C

D) All of the above 

Ans - B

NOTE - Lysine converts into Hydroxylysine by enzyme lysilhydroxylase.

18) Lysil hydroxylase and Propyl hydroxylase enzymes need a cofactor for proper functioning?

A) Lysil oxidase

B) Ascorbic acid 

C) Kinases 

D) Vitamin C

Ans -  D

19) Which of the following is the cause of impaired synthesis of collagen?

A) Deficiency of Vitamin C

B) Excess of Vitamin D

C) Increased level of Insulin 

D) Elevated levels of Thyroid hormone

Ans - A

NOTE - Hydroxylation of proline & lysine needs Vitamin C.

20) Inside the cell where is the site for hydroxylation of Pro and Lys?

A) Golgy body 

B) Lysosome

C) ER

D) Cytosol

Ans - C

21) H-bonded triple standard helical collagen molecule called?

A) Procollagen

B) Tropocollagen

C) Tropoelastin

C) All of the above 

Ans - A

22) Procollagen peptidase cleave amino & carboxyl termini of procollagen and make?

A) Tropocollagen

B) Collagen 

C) Protetin 

D) Option A

Ans - D

NOTE - Self assembly of collagen fibrils via covalent cross linking forms collagen fibers. 

23) Which of the following is a hydrophobic?

A) Elastin

B) Fibrous 

C) Keratin

D) All of the above 

Ans - D

24) Which of the following is highly hydrophobic connective tissue protein which is responsible for extensibility and elasticity?

A) Fibrous protein

B) Elastic protetin 

C) Karetin protein 

D) All of the above

Ans - B

25) Which of the following is true statement? 

A) Elastin protein is present in ligaments, lungs and large arteries in the human body.

B) Tropoelastin is a monomer of Elastin, (72kDa).

C) Elastin protein rich in Proline and Glycine and some Hydroxyproline but no hydroxylysine.

D) All of the Above

Ans - D

26) Peptide bond is rigid because of?

A) Partial Double bond

B) Hydrogen bonding between amino acids

C) Ionic interactions between the amino and carboxyl groups

D) Van der Waals forces between the peptide chains

Ans - A

🐣Tropoelastin = nonpolar - allanine a a & polar segment - lysine rich.

🐣Desmosines fromed from = modifeid Lysine ( tetrafunctional cross link)

🐣Modification of Lysine = deamination of lysine ( removal of omega -NH3+) through enz Lysil oxidase.

5. KERATIN PROTEIN :-

🐣Fribrous protein,

🐣present in = epithelia of all vertebrates, & of two types:

🐣Alfa - karetin (in vegetables) = Tough, nonpolar or insoluble, helical, protofibril

🐣Beta - karetin (in reptiles & birds) = soft and flexible, extended chain, & made from antiparallel beta - pleated sheet.

🐣Alfa - karetin based structures = Horns, scales, claws, hairs, nails, wool feathers etc. 

🐣Polypeptide chain of alfa - karetin = right handed. 

🐣Antiparallel arrangement of prtofilamant - protofibril - microfibril - macrofibril = elastin molecule.

7. MYOGLOBIN :-

🐣Single polyoeptide chain = 153 a a residues.

🐣MW = 17,800 with single heme group.

🐣Inside of myoglobin chain = non polar a a residues & in outside = polar + nonpolar both.

🐣Eight helical segments of heterocyclic ring system.

🐣In heterocyclic ring system = 

🐣and a plot of fractional saturation of myoglobin Y vs partial pressure of O2 (PO2) is = Hyperbolic.

8. Hemoglobin :- i will discuss in next post.